The Food and Drug Administration Sugar Task Force indicated in its 1986 report on the "Evaluation of Health Aspects of Sugars Contained in Carbohydrate Sweeteners" that:
1. the consumption of sucrose and fermentable carbohydrates facilitates the development of plaque, dental caries and periodontal disease, and;
2. the present level of the consumption of sugar within the United States contributes significantly to caries incidence.
In addition to the need to reduce caries incidence, sugar-free confections can be of benefit to those individuals who must regulate their blood glucose and insulin levels. As such, sugar-free confections can benefit certain classes of diabetics.
There are several sugar substitutes which offer potential advantages in the formulation of sugarless confectionery products. Some examples include sorbitol, mannitol, aspartame, saccharine, cyclamate, and of particular note, the sugar alcohol sweeteners xylitol and maltitol.
Xylitol is the sweetest sugar alcohol. It is isosweet to sucrose, and as such, has a sweetness equivalent of 1 0. When utilized in the crystalline form in confectionery applications such as chocolate, chewing gum, re-crystallized candies, and the like a significant cooling effect (temperature lowering effect) is observed as the xylitol dissolves in the mouth. It results from the negative heat of solution for xylitol which is greater than that of all other sugar substitutes.
Xylitol metabolism is independent of insulin. Consequently, xylitol is also a suitable sweetener for the non-insulin dependent (Type II) diabetic.
Many clinical and field studies have demonstrated that sugar-free confections sweetened with xylitol in total or in part, exhibit a cariostatic or caries inhibiting quality. Bumlr, A.: "Caries Prevention with Xylitol" World Review of Nutrition and Dietetics 55:183-209 (1988); "Caries Prevention With Xylitol" Dental Dialogue. A Symposium at the University of Michigan at Ann Arbor (1988). Xylitol sweetened confections have also been shown to alter the polysacoharide composition of plaque--making it less adhesive--and to aid in the reduction of plaque. Soderling, E. et al: "Effect of Sorbitol, Xylitol and Xylitol/Sorbitol Chewing Gums on Dental Plaque", presented at International Association for Dental Research, Montreal (1988). Further, xylitol inhibits the growth of Streptococcus mutans--the major oral bacteria responsible for tooth decay. As such, xylitol is not merely a non-caries causing (noncariogenic) sweetener. Xylitol is an active dental protector.
Maltitol exhibits a lower hygroscopicity than xylitol and a cooling effect (from the negative heat of solution) which is only 15% that of xylitol. In solution, maltitol exhibits a higher viscosity than xylitol at equivalent concentration. The osmotic pressure created by maltitol uptake is notably less than that of xylitol and is similar to that of sucrose. The sweetness equivalent of maltitol is about 0.8-0.9. As such, maltitol is approximately 80-90% as sweet as xylitol.
Because maltitol is not fermented by most oral microflora and a minimal pH drop occurs following its consumption, maltitol can be considered to be a non-cariogenic sweetener. It is not fermented by Streptococcus mutans, but is fermented by Lactobacillus case.
Consumption of maltitol does not produce significant increases in either blood glucose or insulin levels. Maltitol, like xylitol, is a suitable sweetener for the non-insulin dependent (Type II) diabetic.
There are drawbacks associated with the use of either xylitol or maltitol as a sole sweetener, however. With regard to maltitol, its reduced cooling effect in sweetened confectionery products such as chewing gum or mint chocolates can lead to consumer dissatisfaction. And, its reduced sweetness equivalent can lead to confectionery products with insufficient sweetness (chocolate, chewing gum and other confections). With regard to xylitol, its higher osmolality can produce a burning after-taste in the back of the mouth when it is used as the sole sweetener in chocolates and certain other confectionery products. Moreover, its lower viscosity and its low molecular weight can cause poor setting properties in confectionery products such as hard or soft candies or in candies which are subject to cold flow and poor shelf stability.
Therefore, it is an object of the invention to develop a polyol sweetener that is isosweet with sucrose yet does not develop the burning after-taste of xylitol. Another object is the development of a polyol sweetener wherein the cooling effect is modulated to produce the desired sensorical impression. Yet other objects include development of shape retaining properties in formulations of hard and soft candies and development of a cariostatic and/or caries-inhibiting function onto sugar-free confections.